Currently, in the field of video surveillance, valuable dynamic pictures are more concerned when video record files are played back, however in fact the video records usually carry a large number of static pictures without motion information. Thus, a user often looks up a dynamic picture by means of dragging or adjusting a playback speed, when playing back a video record. These means are often easy to miss a dynamic picture required to be concerned, and an operation with a manual means has defects such as low efficiency, low accuracy and inconvenience etc..
<METHOD, SYSTEM AND APPARATUS FOR ADJUSTING A PLAY SPEED OF VIDEO RECORDS> provides a method for parsing and encoding a speed grade in a key frame of video data, utilizing the speed grade to adjust a decoding speed of a decoder and control a media server to selectively read the video data, so as to adjust a play speed of video records.
Its disadvantages are:
(1) the media server selectively obtains the video data from a storage apparatus according to the play speed, which easily leads to a loss of a playback picture.
(2) if a video record file is comprised of many dynamic pictures with small time intervals therebetween within a certain time period, parsing and encoding a speed grade in a key frame of video data to constantly adjust the speed would easily lead to an unsmooth playback.
Wherein, a decoder refers to a program or a device which is able to compress or decompress a digital video.